RESUSCITATION OUTCOMES CONSORTIUM

Version 5: 2-28-11

Biomarker Lactate Assessmentin Shock & Trauma (BLAST)

• State the primary aim of the study.

• State the research question that needs to be answered.

• State the patient enrollment criteria.

• Describe the enrollment decision making process to be use in the field setting.

Learning Objectives

• State the study design including consent requirement.

• Describe the protocol procedures to be performed by EMS personnel.

• Describe the critical documentation that is required for data collection.

• Apply these components appropriately to trauma case examples in a practice environment.

Learning Objectives continued…

• May identify patients Who may not appear to be sick by history or vitals Who may benefit from future ROC trials

• By-product of anaerobic metabolism Where tissues cannot get or process oxygen and

substrates quickly enough

• Biological marker for ischemic organs The final common pathway in many disease states

Why Measure Lactate?

• High lactate levels have been used as a cutoff criteria for illness category in multiple studies.

• Although the meter has not been validated for prehospital use, there is a strong association of lactate levels in trauma and sepsis with morbidity and mortality.

What do the numbers mean?

• Lactate values taken under field conditions may not be accurate. Lactate can be falsely high in patients after seizure or

vigorous exercise.

Lactate levels may be falsely low if there is too little time between the injury and lactate sampling.

• Treating patients based on the point of care lactate level may be dangerous.

Why are we blinded from the Lactate value?

• It is a rapid and easy test to perform.

• May influence the way prehospital triage and care takes place in the future.

• Few studies have looked at prehospital measurement of blood lactate levels.

Why participate in this study?

• Patients meeting local trauma triage criteria for traumatic injury and…

• Systolic blood pressure 100 and…

• Placement of an IV and…

• Transported to a level I or II trauma center or died in the field or en route (with SBP 100 and after placement of an IV).

Quick Guide: Inclusion Criteria

• Age <15

• Hanging; drowning

• Prisoners

• Obvious isolated penetrating head injury

• Primary Burn trauma or blunt or penetrating injury with burns >20% TBSA.

Quick Guide: Exclusion Criteria

• Prepare meter for use

• Open single sealed test strip Fold foil back half-way and hold only by foil

• Place strip gently in meter inlet with tab pointing to the RIGHT of meter

Quick Guide

• A “beep” will sound and “888” will briefly be displayed. Within 2 seconds, the function number (e.g., F-2) and the

last measured test result will blink alternately.

Make sure the function number matches the number printed on the test-strip foil packet.

Quick Guide continued…

• Obtain a drop of blood from patient’s IV.

• Only venous samples are being used.

• Do not delay transport to obtain the lactate.

• Place drop of blood on distal end of strip until meter begins countdown from 60 seconds.

• Dispose of strip in sharps container.

Quick Guide: The Test

Quick Guide continued…

Click inside box to play video

Instructions: Download and insert Lactate Video (Guyette).mpg in this box. Save the video clip in the same folder as this presentation.

• Complete the ROC Prophet documentation.

• A second point of care lactate will be drawn in the trauma bay. If your service is responsible for the second lactate.

Obtain a blood sample from the nurses in the trauma bay and repeat the process.

Quick Guide continued…

After patient care is transferred…

• Please do not remove the red tape from the meter until after you have transferred care.

• Receiving hospital MDs are to be blinded from the lactate value…

Blinding

PLEASE DO NOT TELL THEM WHAT IT IS !

• Place yellow check strip in meter.

• After beep and “888” displayed, second beep is heard, then: Memory sequence starts with screen reading: A (average),

then (value).

Then 1→ (most recent value), 2→ (…20th value).

• Remove check strip when done and place in baggie in meter case.

Retrieving Test Results from Meter

• If EMS uses the same meter to perform both the field lactate and ED lactate: Follow the same procedure. Record the result labeled “1” for the most recent (ED) test.

• Either arterial or venous blood can be used to obtain the in-hospital lactate.

• Record the result labeled “2” for the field lactate test.

• Clear all results from the memory following each patient, to prevent confusion for the next patient’s results.

Recording Both Field & ED Results

• Handle the meter carefully.

• Try to keep within these temps: Meter: 10–40° C (50–104° F) Strips: 1–30° C (33.8–86° F)

• Try not to touch the strips where they contact the machine.

• Keep meter in closed carrying case when not in use.

Storage of the Lactate ProTM

• Every week, check the meter with yellow “check strip.” Pull yellow strip out of baggie, place in meter

Reading should be in range of readout: 2.1–2.6 mmol/L

If outside that range, try again

Still outside the range, call Principle Investigator

Caring for the Lactate Pro™

Lactate Calibration Strip (F5)

Lactate Test Strip

• If meter stops working: Replace batteries: 2 DL or CR2032 Lithium

batteries

Contact ROC

• If meter gets wet: Place in dry room for 2 hours, then try again

If still doesn’t work, call above

Troubleshooting

• What if I use too little or too much blood? An inaccurate result; too much also can clog strip

entry site.

• When do I use the yellow check strip? To perform a quality assurance check once weekly.

Frequently Asked Questions

• When do I use the calibration strip? To start up the meter any time a new box of strips is

used.

• How do I dispose of test strip? Sharps container is best.

Frequently Asked Questions continued…

• Are venous samples consistent with arterial samples?  Several groups have demonstrated excellent correlation

and agreement between venous and arterial lactate in the lab, emergency department and trauma bay.

» Lavery, R. et al. The Utility of Venous Lactate to Triage Injured Patients in the Trauma Center. J AM Coll Surg. 2000, June 190;6; p656-664.

» Gallagher et al. Agreement between peripheral venous and arterial lactate levels. Ann Emerg Med. 1997 Apr;29(4):479-83.

» T. Yoshida. Arterial versus venous blood lactate increase in the forearm during incremental bicycle exercise. 1982 Volume 50, Number 1, 87-93.

Frequently Asked Questions continued…

• Is it minimal risk if we don't draw lactate in trauma bay now? Yes, it is minimal risk because the blood is obtained from an existing

IV site that is placed as part of standard of care. However, if lactate is not part of their routine trauma care I would be concerned that the prehospital value may bias their treatment decisions and elevate this study above minimal risk. We should only obtain a hospital lactate if the clinician feels the patient meets the local guidelines for the collection of these bloods. Some patients who are enrolled in the field will not look bad enough at the ED to result in lactate being drawn at the discretion of the attending physician. As we are not trying to influence practice, this is acceptable. If sites are not wiling to collect hospital lactates, then they might not be eligible for the study.

Frequently Asked Questions continued

• Is it possible to use samples drawn from an IO? There is no data on this.

The marrow is a venous plexus, but there is uncertainty of the effect of fat and other marrow contents might have.

Interesting question for another study, and IO samples should be excluded.

Frequently Asked Questions continued

• Will capillary samples be collected, or will only venous samples be acceptable?   Capillary sample values are significantly higher than the venous samples.

» That may be due to a variety of confounding factors (patients who are hypoperfused or dehydrated may be more difficult to gain IV access).

» Other potential issues may include milking the finger to get a capillary sample or artificial elevation in a poorly perfused digit (due to cold, hypoperfusion, or sympathomimetics) as compared to a venous sample. 

There is unpublished data from an in-house study comparing a different POC meter and venous draws sent to a lab. There is very poor agreement between the two measures.

There is concern that a capillary blood draw, although arguably minimal risk, is invasive. It may be difficult to convince many IRB’s that it can be done under waiver.

Frequently Asked Questions continued

Prehospital Documentation

BLASTBiomarker Lactate for the

Assessment of Shock in Trauma

• Call received

• Arrival on scene

• Arrival at patient

• Arrival of ALS

• Time of Placement of Vascular Access

• Time of Point of Care Lactate done

Prehospital Time Record

• IV Access

• First SBP <100

• Second IV access (if applicable)

• Point of Care Lactate (done at hospital if applicable)

Event Times

• Catheter location

• IV catheter gauge (size)

IV Start Data

• Lactate obtained during IV insertion

• Lactate value during transport _____ mmol/L

• Lactate value at hospital _______ mmol/L

• IV Fluids Administered Volume before Lactate _____ml Volume after Lactate ______ml Total Volume _______ml

Lactate

(Add site-specific information)

Contact 24/7 for any and all questions or concerns: